Speaking on the Andrew Marr Show this morning, Abbott tried to play down the row which has engulfed the party in recent days.

The Shadow International Development Secretary argued Labour does not have a problem with anti-Semitism, claiming there had been just 12 such incidents since Jeremy Corbyn became leader – all leading to suspensions.

She also said that if Corbyn’s opponents in Labour triggered a fresh leadership election off the back of the row, the current leader would win easily.

Another of Corbyn's allies, Unite General Secretary Len McCluskey, later told BBC Radio 5 Live’s Pienaar’s Politics the anti-Semitism storm was merely “mood music” being used to challenge Corbyn’s leadership.

Speaking on the BBC this morning, Abbott described former London Mayor Ken Livingstone’s claim that Adolf Hitler was initially a Zionist as “extremely offensive” – adding: “He was suspended within hours.”

She then said: “Ken will have due process and the party will decide what happens. It’s something of a smear against ordinary party members. It’s a smear to say the Labour Party has a problem with anti-Semitism.

“There’s issues about process. There’s nothing in the rules about anti-Semitism, racism or Islamophobia. We are going to make the rules explicit.”

Abbott defended Labour’s record of “standing up to anti-Semitism” before it was “fashionable.”

She added: “Anybody who says Jeremy Corbyn is an anti-Semite cannot sustain that argument.”

It is no good some people denying anti semitism is a problem. It is. And pouring petrol on it and denouncing the messenger does not help.

Abbott also suggested that any of Corbyn’s enemies in the party who would use the row to trigger a leadership challenge would be left disappointed by the outcome.

She said: “These are people who did not accept the result of last summer’s leadership election.

“We’re talking about people who’s candidate got four and half per cent [Liz Kendall] ­– Jeremy got 60 per cent.

“I think it would be very unfortunate if we had another leadership election, the party can scarcely afford it financially, and more important the party should be concentrating on fighting the Tories, but if people are intent upon having a leadership election then we may have one.

“But I have to say to you if Jeremy is on the ballot, Jeremy wins, all the polling shows that Jeremy is as popular with Labour Party members now as he was when he was first elected.”

The row kicked off this week when it emerged that Bradford West MP Naz Shah had shared posts and made comments on Facebook deemed to be anti-Semitic.

Labour initially decided not to suspend her from the party, but after she issued a fulsome apology in the Commons on Wednesday she was suspended.

Speaking on Pienaar's Politics this morning, McCluskey echoed Abbott's view that the anti-Semitism row was overblown.

He went further than the Hackney MP in his criticism of Labour MPs in the party who don't support Corbyn's leadership, saying: "The first thing they do when they wake up of a morning is think of what stick can we beat Jeremy Corbyn with."

He added: "It’s how they treat the leader and a number of them, a small number of them, always treat the leadership with utter disrespect. It’s interesting that they always have a microphone handy whenever they want to have a go at Jeremy. Once this, the mood music of anti-Semitism dies down then next week, and the week after, there will be another subject."

When challenged on the phrase "mood music", McCluskey said: "That’s what’s being created here. The idea that there is an anti-Semitic crisis in the Labour party is absolutely offensive. But it’s being used to challenge Jeremy Corbyn."

Also appearing on The Andrew Marr Show this morning was Israel’s ambassador to the UK, Mark Regev.

He said he would “love” to meet Corbyn to discuss the issue of anti-Semitism, and urged the Labour leader to visit Israel.

Regev also made a thinly-veiled dig at Corbyn’s previous association with terrorist group Hamas, which he reportedly once described as “friends”

Regev said: “You’ve had too many people on the progressive side of politics who have embraced Hamas and Hezbollah. Both of them are anti-Semitic organisations, you just have to read Hamas’ charter and it’s like chapters straight out of the Protocols of the Elders of Zion. Yet some progressive politicians have embraced Hamas.

“Now, I’d ask the following question: if you’re progressive, you’re embracing an organisation which is homophobic, which is misogynistic, which is openly anti-Semitic, what’s progressive about that?”